G9700 outputs

Good choice. I did the same and found that the G9700 runs cooler at higher volumes probably due to the additional headroom of the 2608/1117 pairs.
With the volume set to 4, things are earth shaking. -Again, just added headroom.


Hope all turns out ok for you.

moe of the North.



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Not exactly sure what or why it happened but I came home from work one day and turned it on and was about to play some music when a puff of smoke came out of it? needless to say I took it apart a few days later and found all of the right side op's were shorted and upon further investigation a bunch of resistors were fried on the right driver f-3074 and on f-3073 I found a couple of transistors and resistors were also fried I replaced about every,transistor,resistor,trimmer and electrolytic cap on both sides f-3074,f-3073,f-3072 and put some Mj21194g,93g op's in it for now and everything is working fine again..Now I'm just waiting for the new op's to arrive..
 
It seems odd that all the op's were toast on one side? I burned up one set right side and similiar to your situation, found misc resistors/transistors on that side had taken the hit upstream of the 2607/11116 pairs. Also found that 2 of the 33k thermos resistors had fried as well, not sure if you've replaced or checked yours 33k thermos but be suspect.
I forgot to mention the .33k emitters on the right one was cracked in half and two were way off specs so I replaced all of them both channels.
 
It seems odd that all the op's were toast on one side? I burned up one set right side and similiar to your situation, found misc resistors/transistors on that side had taken the hit upstream of the 2607/11116 pairs. Also found that 2 of the 33k thermos resistors had fried as well, not sure if you've replaced or checked yours 33k thermos but be suspect.
I've been playing this at low levels with the sacrificial Mj21194g,93 op's for a month or so now with zero problems accept for the first time I put them in and forgot that they were lower power and when I turned it up about half throttle it blew the whole right side(op's only)..been playing about everyday for an hour or so on half to three quarter volume with no problems ever since..
 
Those MJ15003/4's have caught my eye too lately as McIntosh is quite fond of them.
However have had nothing but good luck with the 93/4's and never seen one fail.
MJ15003/4's are much older than MJ21193/94 series.
I used MJ15003/4's in my pioneer sx-950 years before MJ21193/94 series became available. If i did it again of course I'd choose MJ21193/94 series
 
I've been playing this at low levels with the sacrificial Mj21194g,93 op's for a month or so now with zero problems accept for the first time I put them in and forgot that they were lower power and when I turned it up about half throttle it blew the whole right side(op's only)..been playing about everyday for an hour or so on half to three quarter volume with no problems ever since..

This is not making any sense to me at all... You are saying the MJ2193G/94G are lower power than the originals? I don't think so...... Not even close really. I think you have an underlying issue you have not found that keeps taking the amp out. No way should the MJ21193G/94G outputs blow before the originals would.

That said, I think your very rare replacements are also in jeopardy until you figure out what is causing the channel to nuke itself.
 
I've been playing this at low levels with the sacrificial Mj21194g,93 op's for a month or so now with zero problems accept for the first time I put them in and forgot that they were lower power and when I turned it up about half throttle it blew the whole right side(op's only)..been playing about everyday for an hour or so on half to three quarter volume with no problems ever since..

If that's happened you have some other issue, the MJ21193/4 are most likely twice the voltage and twice the current of the original....
 
If that's happened you have some other issue, the MJ21193/4 are most likely twice the voltage and twice the current of the original....
The only board on the power supply section that I didn't touch is the RF power supply board F-3071..The bias and dc offset adjustments are right on..I checked and rechecked the adjustments and they haven't changed at all..
 
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The bias and dc offset adjustments are right on..I checked and rechecked the adjustments and they haven't changed at all..

If this is true then you may be fighting an oscillation issue.
 
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The bias and dc offset adjustments are right on..I checked and rechecked the adjustments and they haven't changed at all..

If this is true then you may be fighting an oscillation issue.
It plays just fine unless I turn the volume up half way with the loudness button on then it go's into protection after 30 seconds or so but with loudness button off it continues to play just fine.
 
If this is true then you may be fighting an oscillation issue.

Most likely, this is the problem. It may not show up at all times either. The amp needs to be seen on a scope.

Check that all the emitter resistors and base resistors are in range. Then I would replace the drivers and pre-driver transistors. All of them. The pre-driver transistors are always toast in these receivers. The drivers need replaced simply because every time the amp blows, they are getting beat on. They cannot be trusted anymore.
 
It plays just fine unless I turn the volume up half way with the loudness button on then it go's into protection after 30 seconds or so but with loudness button off it continues to play just fine.
Also at half volume the power meters are pegged out at 200w..
 
It plays just fine unless I turn the volume up half way with the loudness button on then it go's into protection after 30 seconds or so but with loudness button off it continues to play just fine.
This sounds like excessive DC or a tired protection circuit problem. Most likely another and different problem than the blowing channel.

Although, half volume on this receiver is REALLY FRIKIN LOUD dude. Might not be a damn thing wrong with anything if you are over-driving it. From what you just said, I am inclined to believe that the receiver is trying to protect itself, from you.
 
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This sounds like excessive DC or a tired protection circuit problem. Most likely another and different problem than the blowing channel.

Although, half volume on this receiver is REALLY FRIKIN LOUD dude. Might not be a damn thing wrong with anything if you are over-driving it.
I replaced every transistor,electrolytic cap and most of the resistors in the power supply,drivers and protection circuit.I didn't replace the relays or any jfets and I didn't touch the RF power supply board..
 
This sounds like excessive DC or a tired protection circuit problem. Most likely another and different problem than the blowing channel.

Although, half volume on this receiver is REALLY FRIKIN LOUD dude. Might not be a damn thing wrong with anything if you are over-driving it. From what you just said, I am inclined to believe that the receiver is trying to protect itself, from you.
I like to give my stuff a stiff test once in awhile :)
 
I replaced every transistor,electrolytic cap and most of the resistors in the power supply,drivers and protection circuit.I didn't replace the relays or any jfets and I didn't touch the RF power supply board..
Curious how much power you are putting out at half volume then. Should be just about all she's got captain.
 
Curious how much power you are putting out at half volume then. Should be just about all she's got captain.
Ya I'd like to get it checked out on a scope or something to check for oscillation but nobody around here does it that I can find..
 
The meters are giving you a rather inaccurate reading on what the amp is really doing but I digress. The volume control adds gain to the input signal up to the output voltage limit of the amplifier. The higher the input voltage the faster the amp reaches its maximum output. Modern sources tend to drive much higher input values than those of 30 years ago causing the amp to reach clipping much sooner i.e. by 11 o'clock on the knob rather than 2 o'clock (reference points don't take literally). Also, much as the loudness control adds bottom and top end gain it is really really hard on tweeters when you drive them that hard. Finally, other factors come into play such as speaker efficiency and speaker loading. The only true way to diagnose a suspected amp is to run it up on a scope and dummy loads observing the generated waveform for abnormalities. As MMA said, 12 oclock on a 9700 is loudddddddddddd :)
 
I wonder what speakers and source are you using, can it be you just that you are driving your receiver beyond its capabilities?
 
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From what I have seen of the rest of this series (G-4700 thru G-7700) I would never rule out oscillations as a possible/probable cause of problems. They can come, and they can go. And they often leave the magic smoke as an indicator.
 
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